Title page for ETD etd-06122010-020246

Formulation of improved media for isolation and cultivation of Campylobacter fetus.

Degree

Master of Science

Department

Microbiology

Advisory Committee

Advisor Name

Title

Krieg, Noel R.

Committee Chair

Smibert, Robert M.

Committee Member

Wilkins, Tracy D.

Committee Member

Keywords

pathogens

Date of Defense

1977-12-15

Availability

restricted

Abstract

Campylobacter fetus, a microaerophilic, Gram-negative rod, is a
well-known cause of contagious abortion and infertility in cattle and
sheep and is gaining increasing recognition as an opportunistic
human pathogen. In the past, the unusual oxygen requirements of the
organism have complicated its recovery from clinical sources; optimum
recovery necessitates the use of special gas mixtures, vacuum pumps,
etc., not routinely used in most laboratories. In this study, the
stimulatory effects of compounds found to enhance aerotolerance and
growth of C. fetus were tested for 62 strains of C. fetus, representing
each subspecies, to test the desirability of supplementing conventional
media with these additives. Brucella agar supplemented with 0.025%
(each) FeS04·7H20, sodium bisulfite, and pyruvic acid (FBPA agar)
supported growth of 82% of the strains tested under simulated candle
jar condtions. Brucella broth supplemented with 0.2% FeS04 ·7H20,
0.025% sodium bisulfite, and 0.050% pyruvic acid (FBPB broth) supported
growth of 61 of 62 strains at 21% 02, 2.5% CO2 with static incubation.

Therefore, FBPA agar and FBPB broth are recommended for the
isolation and cultivation of C. fetus. Although isolation from
clinical sources is still dictated to some extent by the oxygen
tension used for cultivation, improved recovery may be expected
regardless of equipment or facilities available.
Another compound found to enhance aerotolerance of C. fetus
was SOD. This finding supports the hypothesis that the stimulatory
effect of the media additives results from a direct action on the
culture medium by degrading toxic derivatives of oxygen, such as
the superoxide radical and hydrogen peroxide.